... •Grade 275 series steel for all members•All steel area to be painted shall be primed with a coat of red lead primer or 1 coat of zinc chromate primer •All steel purlins and all steel members for ... purlins and for building 5 storey and above shall be zinc-electroplated Steel = 98% of Iron with Main Alloying Steel = 98% of Iron with Main Alloying Elements Carbon, Silicon, ManganeseElements ... the brittle the steel •Grade 43 ( most common ), 50 and 55 (strongest) Design Grade -> Thickness -> Design Strength•Hot Formed and Cold Formed Hollow Sections•Simple Design •Pinned joints,...